Lighting system for tubular lamps and holder for use therein



June 4, 1946. F. c. DE REAMER LIGHTING SYSTEM FOR TUBULAR LAMPS AND HOLDERS FOR USE THEREIN Filed Nov. 7, 1944 Patented'June 4, 1946 LIGHTING SYSTEM FOR TUBULAR LAMPS AND HOLDER FOB USE Frank C. De Beamer, Bridgeport, Conn., assignor to General Electric Company, a corporation ol New York Application November 7, 1944, Serial No. 562,363

4 Claims. (Cl. 315-193) The present invention relates to lighting systems for tubular lamps, such as iluorescent lamps, wherein a number of.` lamps are operated in a series circuit, the arrangement being such, for example, that the lamps provide a continuous line of light. Such a series requires a high voltage for its starting and operation. For example, such a system may utilize a Voltage as high as 15,000 volts. In the case of an ordinary lighting circuit, the high voltage is obtained from the usual 115 volt circuit by means of a suitable transformer which has its .primary connected to the lighting circuit and its secondary connected to the lamp circuit.

The object of my invention is to provide an improved system which affords a, high degree of safety and improved lamp holders for use in such a system.

For a consideration of what I believe to be novel and my invention, attention is directed to the following speclcatlon and to the claims appended thereto.

In the drawing, Fig. 1 is a side elevation showing a number of tubular lamps, three in the present instance, ypositioned in a series of spaced holders embodying my invention; Fig. 2 is a view similar to Fig. 1 with the lamp holders in section and on a larger scale, with the lamps broken away at their central portions and with a wiring system diagrammatically connected to the lamp holders; Fig. 3 is a transverse sectional view taken on line 3 3, Fig. 2: Fig. 4 is an end view of either of the end lamp holders, the two being alike in this respect, and Fig. 5 is a view partly in section illustratlng the way in which a lamp is inserted into the lamp holders.

Referring to the drawing, I indicates a series of tubular lamps positioned in end holders 2 and 3 and intermediate holders 4. In Fig. 1, three lamps are illustrated so that there are two intermediate lamp holders 4.

End lamp holder 2 comprises a casing 5 of sultable insulating material having walls which define an annular recess 6 and a second recess 1 y separated by a wall 8. The open side of recess 1 ls closed by a cover plate 9 held in position by screws I0. In its top wall is a terminal post I I in the outer end of which is threaded a terminal screw I2 by means of which an electrical conductor may be attached to the terminal post. The inner end of terminal post II is positioned in recess 1 and is connected by a exible conductor I3 to the end of a contact pin I4. Contact pin I4 is positioned in a sleeve I5 of insulating material Y sude through such opening. Pin I4 1s held in the sleeve by a head 5I) at one end of the pin and a collar 5I on the pin. Located in recess 6 on the end of sleeve I5 is a cup-shaped housing I6 which surrounds and houses the other end of contact pin I 4. The cup-shaped housing I6 has a flange at its free end between which and wall 8 is located a spring I1 which biases the cup-shaped member IB and sleeve- I5 to a position wherein head 50 on the end of the contact pin, which is located in recess 1, is against wall B. Sleeve I5 can slide through the opening in wall 8 until its end engages cover plate 9.

Lamp holder 3 comprises a casing 20 having walls which dene a chamber 2l and a chamber 22. The chambers 2I and 22 are open yat their upper ends as viewed in Fig. 2 and are closed by a cover plate 23. The open endof chamber 22 is closed by a cover plate 24. Carried by cover plate 23 is a terminal post 25 provided with a terminal screw 26 in its outer end by means of which a lead wire may be connected to post 25. The inner end of terminal post is connected by a flexible conductor 21 to one end of a contact pin 28 25 positioned in a wall 29 which separates chamber tact 33 and the movable contact 34 of an electric switch. Contacts 33 and 34 are connected to terminal posts 35 and 36, respectively, which are carried by cover plate 23 and are provided at their outer ends with binding screws 31 and 38 to which electrical conductors may be connected. Switch contact 34 is biased to a position away from :fixed contact 33 as shown in Fig. 5, the switch being normally open when a lamp is not in position in the lamp holder.

Lamp holder 4 comprises a combination of lamp holders 2 and 3 diiering from them primarily in that the contact pins instead of being connected to contact posts are connected to each other by a flexible conductor 40. Accordingly, there has been applied to the parts of lamp holder 4 reference characters the same as those applied to corresponding parts of lamp holders 2 and 3J except that the exponent a has been added. The construction of lamp holder 4 will be obvious from the explanation already given of the constructions of lamp holders 2 and 3.

located in an opening in wall 8 and adapted to 55 Each lamp comprises atubular envelope 4l having attached to its ends insulating sleeves 42, each provided with an opening 43 in which is embedded a lamp terminal 44. The openings 43 are of a size to receive the ends of the contact pins I4, Ila and 28, 28a. A lamp provided with lamp ends of this type is disclosed and claimed in the application of De Reamer and Pistey, Serial No. 559,990, illed October 23, 1944.

Referring particularly to Figs. 2 and 5. it will be seen that a lamp end may be inserted into the recesses and 5*, the chambers being of a diameter greater than that of the lamp. However, with respect to the end lamp holder 3 and the left hand side of the lamp holder 4, as viewed in Fig. 2, the end wall is provided with a shoulder 45 or 45 with which the end of the lamp engages. with the shoulder 45 or 45, contact pin 32 or 32a is in engagement with "a lamp contact 44, and the end of sleeve 42l engages the movable contact 34 or 34"L of the switch to bring the movable contact into engagement with the corresponding stationary contact.

Referring to Fig. 2, 52 indicates a transformer having a primary winding 53 and a secondary winding 54. The primary winding is connected to a source of electric energy 55 and to the contacts 33 and 34 of the end lamp holder 3 and the contacts 33nl and 34 of the intermediate lamp holder 4. If additional lamp holders 4 are in the series, then the switch contacts of each of them likewise would be connected through the primary winding of the transformer to the source of power, all the switches being in series. The secondary winding 54 of the transformer is connected to the terminal posts ll and of the two end lamp holders 2 and 3. With this arrangement, it will be seen that the circuit on the primary of the transformer is not completed un-r` til all the lamps of the series have been positioned in theiry holders; and that the circuit of the primary is opened whenever a lamp is removed from the circuit. Also, since the lamp must be inserted in a holder which does not embody a switch before it can be inserted in a holder embodying a switch, it is not until the last lamp has When a lamp end is in engagement been nally completely positioned in the holders that the primary circuit is closed.

I'he manner oi inserting a lamp in the holder is illustrated in Fig. 5. The lamp 4l is rst positioned in the holder 2, the one la'mp terminal 44 being brought into engagement with the contact pin I4. after which the lamp is pushed to the left against the action o! spring Il as shown in Fig. 5 until it reaches a position where its other end can be brought up into line with lamp holder 3. It is then permitted to move to the right as shown in Fig. 5 to bring the other lamp contact 44 into engagement with the end 32 of pin 28 marily with a number of lamps connected in series, it may of course be used in connection with a simple lamp, the installation then embodying only a lamp holder 2 and a lamp holder 3 as shown in Fig. 5.

By my invention, I provide a wiring `system for a series of lamps which offers a high factor of safety since as soon as removal of any one lamp is started,r the circuit is disconnected and cannot be reestablished until all lamps are in place.

Also, the la'mp holders for the system are relatively simple in structure, reliable in operation, and capable of being manufactured at low cost.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a lighting system, a pair of spaced apart lamp holders for holding and connecting in circuit: a tubular lamp, lamp terminal engaging contacts in said holders, a' normally open switch in one of said lamp holders which is closed by the insertion .of a lamp therein, and a transformer having its secondary connected vto said lamp terminal engaging contacts and its primary connected to line through said switch.

2. Means for supporting and connecting into circuit a tubular lamp having contacts at its ends comprising a pair of lamp holders between which the lamp is inserted having contacts for engagement with the lamp contacts and a switch which is closed when a lamp is inserted into the holders, and means forming parts of said lamp holders whereby a transformer may have its primary connected to line through said switch and its secondary connected to the lamp holder contacts.

3. In a lighting system for a plurality of tubular lamps operated in series, spaced apart end and intermediate lamp holders between which the lamps are positioned, lamp terminal engaging contacts in said holders, a normally open switch in one of the end lamp holders and in each intermediate lamp holder, said switches being closed by the insertion of lamps between the lamp holders, and a transformer having its secondary connected to the two end lamp holders to connect the lamps in series circuit and its primary connected to line through said switches in series.

4. In a lighting system, tubular lamp holding means comprising a pair of spaced lamp holders having spring biased axially movable contacts adapted to be engaged with lamp end contacts by endwise movement of a tubular lamp positioned between the holders, one of said holders having an opening of an area such that a lamp end may be passed through it a distance sufficient to permit the other end of the lamp to be brought up into line with the other lamp holder, said other lamp holder having stop means to limit the distance a lamp end may move into it, a normally open switch in 'said other lamp holder which is closed when a lamp end is positioned in such other lamp holder, said stop means beingy so 1ocated that a lamp can be positioned in the lamp holders only by first positioning it in the said one lamp holder and a transformer having its secondary connected to said contacts and its primary connected to a line current supply through said normally open switch.

' FRANK C. DE REAMER. 

